Many species of boring beetles frequently attack aspen. The most important is Saperda calcarata, a round headed, long-horned beetle. However, the damage is similar regardless of the boring insect involved. These insects attack stressed trees, usually caused by the lack of water or planting to low. The damage is caused by developing larvae which feed in the trunk of the aspen for several years. Their tunneling often weakens the wood of the trunk and allows invasion of insects, canker and decay fungi.